1. Field of the Invention
This invention relates to trailers for towed vehicles and more particularly to single axel trailers of the type which support only one pair of vehicle wheels. It is particularly directed to steerable trailers for farm vehicles such as tractors where the front wheels of the tractor are supported and the trailer is towed as by a truck while the rear tractor wheels support the remainder of the vehicle weight on the ground or road surface.
2. Description of the Prior Art
Heretofore it has been known to transport tractors by placing only their front wheels on a single axel trailer. Stanley et al. U.S. Pat. No. 2,661,856 of Dec. 8, 1953 discloses a mechanism styled "Dolly for supporting Tractor Front Wheels". Stanley et al. are concerned with a tricycle type tractor and hence their dolly has a narrow track and can have its axis of rotation of its wheels fixed normal to the draw bar of the dolly. The dolly includes a cradle for the tractor front wheels and a front chock plate against which the wheels are secured as by a length of chain.
In Denny U.S. Pat. No. 3,494,635 of Feb. 10, 1970 entitled "Vehicle Tow Trailer" and U.S. Pat. No. 3,653,680 of Apr. 4, 1972 entitled "Tow Trailer With Folding Carrier Platform" single axel trailers with steerable wheels are shown having rearwardly extensible vehicle support elements as might be employed to support one end of a disabled vehicle having the wheels on the other end operative for rolling support of the vehicle. Denny teaches a steering mechanism for the trailer wheels to cause them to track the angular relationship of a tow bar or draft bar with respect to the transverse axis of the trailer and means to lock the steering mechanism and tow bar relationship normal to the transverse axis of the trailer.
Farmers frequently work widly spaced fields under circumstances which require the transportation of working vehicles such as a farm tractor or combine together with a conventional over-the-road vehicle such as a pickup truck by a single man. Where a wide tread vehicle is to be transported it is desirable that the single axel trailer employed have steerable wheels thereby effectively converting the working vehicle to a four wheel trailer. Such trailers should be low to enable the wheels of the vehicle to be towed to be driven up on the trailer. It therefor has low ground clearance, a disadvantage on severe roads and rough terrain. Prior art devices have not offered a secure mount for the towed vehicle wheels nor suitable means to overcome difficult terrain.
An object of the present invention is to improve trailers for towed vehicles particularly rough terrain trailers of the single axel type.
Another object of the invention is to more securely retain the wheels of towed vehicles in a wheel support on a trailer.
A third object is to insure a single axel trailer for a towed vehicle will effectively steer that vehicle even when steering mechanism for the trailer has not been made operative.
A fourth object is to enable an underslung trailer to operate over rough terrain by skidding relationship with the underlying terrain.
A fifth object is to accommodate a range of towed vehicle wheels in abutting engagement with wheel supports on a towed vehicle.